Engine-starter.



the

VINCENT BENDIX, OF CHICAGO, ILLINOIS.

ENGINE-STARTER.

Specification of Letters Patent.

Patented Feb. 29, 1916.

Application filed April 26, 1915. Serial No. 24,029.

To all whom it may concern:

Be it known that I, VINcnN'r Bnnnlx, a cltizen of the United States, residlng at Chicago, in the county of Cook and State the like characterizei'l by the employment of a screw-shaft operated by a motor and a pinion screw-tlnezuled upon the shaft and ttlfl]')t6(l to travel longitiulinally in one (ii-- rection along theshaft into engagement with. the rotary member of the engine to be started and to travel longitudiiniliy in the opposite direction after being automatically thrown out of engagement with the engine member when the engine begins to run on its own power.

The object of this invention is to provide a simple and cllicient driving connection between the motor such as an electric motor and the screw shaft which connection is characterized by being of a yielding nature and also one permitting a slight longitudinal movement of the screw shaft to a purpose hereinafter explained.

In the drawing the figure represents a sectional elevation of a portion of an electric motor and the screw shaft. and. pinion together with the yielding driving connections constituting themain feature of this invention.

Referring to the ei'nhodimei'it of my inventiOn as herein shown the prime n'iover is here an electric motor 1: whose armature shaft is by preference extended to form the driving shaft 2. This motor is mounted within a casing 3 which also contains or incloses the transmission mechanism including the screw-shaft, pinion and yielding driving connections with the driving shaft 2, and also provides an outboard hearing at for the outer end of the scrw shaft.

The screw shaft 5 is screw-threaded as to its intermediate portion, its outer portion being mounted to rotate in a 'loushing 6 in the bearing .i: and its inner end being operatively connected with the armature or driving shaft 2 in the manner hereinafter explained. The pinion 7 is screw-threaded anon the screw-shaft and is ada ted tov travel longitudinally thereon and also rotarily therewith, the same being adapted to engage some rotatable member of the engine such as the circular rack 8 on the fly wheel 9 of such engine.

The armature or driving shaft 2 is secured in suitable manner as by means of the key 10 to a sleeve 11 fitting upon such armature shaft and also upon the inner cylindrical end of the screw-shaft which is consequently in alinement with the armature shaft. X spring '11. which is coiled around the sleeve constitutes the yielding dri 'ing connection between the driving shaft 2 and the scrmvshaft and fol-this purpose one end of the spring is secured to the sleeve and the other to the screw-shaft. As shown the inner end of the spring has a' loop or eye it which is anchored to a stud lf r which, in the present instance, passes through the sleeve and enters the driving shaft although it is not necessary that it enicr the latter but only engage the sleeve, In the present instance where this stud passes into the driving shaft 2- it is not necessary that the key 10 be employed although I prefer to do so The other or outer end of the spring terminates in a loop or eye 15 which is anchored to the stud '16 which enters the cylindricai portion of the screw shaft. This latter stud enters the screwshaft at a point slightly in advance of the outer end of the sleeve 11 and the adjacent ends of the driving shaft and the screw shaft are also slightly sepa rated with the result that the screw-shaft and the sleeve are capable of telescoping action so as to permit of a slight longitudin'al'movement of the screw-shaft.

From the foregoing description it will be midcrstood that the spring it? constitutes a yielding driving connection between the motor and the screw-shaft the driving being from the driving shaft 2 to the sleeve 11 thence to the spring 12 and finally to the screw-shaft.

By the provision of the yielding driving connection better starting action is obtainable particularly in that the pinion is kept in mesh with the engine member such as the fly Wheel when the engine is passing over the compression points With the result that vibration of the pinion on the screwshaft during the operation of the engine is prevented. This result is accomplished by the provision of the spring 12 which is capable of increasing the speed of the screwshaft Whenever the load of the shaft is relieved to any extent, that is when the engine has just passed over the compression point.

stantaneous and takes its place faster than the motor can pick vup and transmit increased speed so that the variable speed of the engine has no effect upon the starting operation.

Another practical advantage obtained'by. my yielding driving connection is the elimination or absorption of shock atthe time when the pinion ceases its longitudinal travel and starts to rotate with the shaft, which time is represented by the contact between the lug 17 projecting forwardly of the pinion and the lug or stop 18 on the screw shaft. This contact is not abrupt or forcible but is cushioned by reason of the yielding driving connection.

Still another practical advantage which resides in the fact that in case the teeth of the pinion and rack 8 should be in alinement and thereby contact end to end, such contact will be cushioned by reason of the fact that the screw-shaft is capable of a slight yielding movement with respect to the sleeve 11 which movement is resisted by the spring 12.

I claim:

l. A starter for engines comprising a shaft havinga screwsthreaded portion and a cylindrical inner end, a driving device which is screw-threaded up toengage a part of the engine to be driven, a motor having a driving shaft in axial alinement with shaft, a sleeve fitting over the ends of c ih shafts, and secured to to engage a part of the on the shaft andadapted to travel longitudinally, thereon and the driving shaft, and a yielding driving connection between the sleeve and screw a cylindrical inner end, a driving device which is screw-threaded upon the shaft and adapted to travel longitudinally thereon and a motor having a driving shaft in axial alinement with the shaft, a sleeve fitting over the ends of both shafts, and secured to the driving shaft, and a spring coiled around the sleeve with its ends anchored to the sleeve and screw-shaftrespectively.

3. A starter for engines comprising a shaft having a screw-threaded portion anda cylindrical inner end, a driving device which is screw-threaded upon the shaft and adapted to travel longitudinally thereon and engage a part of the engine to be driven,

'a motor having a driving shaft in axial engine to be driven,

alinement with the shaft, a sleeve fitting over the ends of both shafts, and secured to the driving shaft, the adjacent ends of the two shafts being normally separated to permit of a longitudinal movement of the screwshaft within the sleeve, and a yielding driving connection between the sleeve and screwshaft.

' v VINCENT BENDIX.

Witnesses 4 S. E. Hmnnn, Bonner Doseernas. 

